1. Field of Invention
The present invention relates to a wireless communication terminal such as a mobile phone, more particularly relates to a wireless communication terminal having two housings connected so that they can be opened and closed with respect to each other and having a built-in antenna in one housing.
2. Description of the Related Art
In recent years, portable wireless communication terminal such as mobile phones and PDAs having a wireless function provided with a first housing, a second housing, and a hinge pivotally connecting the first housing and the second housing and configured so that the two housings can be opened and closed have become popular.
Now, however, smart designs are now being demanded from wireless communication terminals. A wireless communication terminal arranging the antenna in the first housing or the second housing forming part of the terminal in place of an antenna sticking outside of the housing as in the past has been proposed (see for example Japanese Unexamined Patent Publication (Kokai) No. 2001-284934). The wireless communication terminal disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2001-284934 is a fold up type which has a built-in antenna in the hinge.
In the wireless communication terminal disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2001-284934, use is made of a flexible circuit board and interconnects for electrically connecting the circuit boards etc. arranged in two housings. These are inserted into the hinge. Therefore, there is the disadvantage that it is difficult to arrange the antenna there in terms of space. Further, the flexible circuit board and the interconnects would be near the antenna, therefore they would be liable to have an adverse effect on the antenna characteristics.
Therefore, a wireless communication terminal arranging a built-in antenna in an end of the housing has been proposed. However, in a wireless communication terminal such as mobile phone, the positional relationship between the antenna provided in one housing and the other housing changes according to the opening/closing of the terminal, therefore the antenna characteristics would change between the opened state and the closed state.
The antenna used in a mobile phone etc. is adjusted in its resistance so as to become 50Ω. If the built-in antenna is arranged in the end of the housing, when the first housing and the second housing are in the closed state, the antenna would be arranged facing the vicinity of a speaker or microphone arranged in the end of the other housing, while when the housings are in the opened state, the antenna would be arranged far from the speaker or microphone. Therefore, the impedance characteristic would change between the closed state and the opened state, so there would be the disadvantage of a deterioration in the reception characteristics.